Rafael Nadal pleased that hard work is showing in results

Rafael Nadal celebrates after winning the Barcelona Open

Spanish tennis star Rafael Nadal has said he was starting to see the results of his persistent work at practice.

"For months now I've been saying I feel good, that I'm enjoying the competition, the training, that the feeling is different from last year, but if that's not accompanied by results they're just words," Nadal said here on Friday.

The Mallorca native said it was "more fun to learn while winning instead of losing".

"The learning process is the day-to-day, the experiences that you go through throughout your career, and in your life in general, and from all that you take the things that are useful to you and discard the rest," the 14-time Grand Slam champion added.

He said all he had done in recent months was work every day in practice with the "necessary hope" that he could improve after struggling with nerves and anxiety in a difficult 2015 season.

The 29-year-old did not win any of the four Grand Slam events or nine ATP World Tour Masters events in 2015, the first season since 2004 that he failed to capture any of tennis' biggest titles.

The Spaniard also lost in the first round of this year's Australian Open, but he has bounced back in recent weeks, reaching the semi-finals of last month's Indian Wells hard-court event and winning two titles on his favoured clay surface in April: the Monte Carlos Masters and the Barcelona Open.

He will compete in next week's Madrid Open, also a clay-court Masters 1000 tournament, as he continues to make preparations for the French Open, which gets underway on May 22.

The fifth-ranked Nadal has won French Open nine times, the most singles titles captured by a male player at one Grand Slam tournament.

The Spaniard has only lost twice at the French Open in his career, but one of those defeats came last year against Serbian World No.1 Novak Djokovic.